It helps to know people in your own and in peripheral industries.
If you are a computer programmer you might benefit by knowing a graphics designer.
If you are an auto mechanic you might benefit by knowing an auto body artist.
If you are a real estate professional you can embellish your repertoire knowing home inspectors, lawyers, construction contractors, painters, surveyors, property managers, plumbers, electricians, roofers, insurance brokers, mortgage agents, accountants, and community leaders.
As a real estate professional, you are inevitably reliant on the expert advice of your peripheral professional circle.